1. Field of the Invention
The present invention relates to a seal for a toner cartridge and, more particularly, to a process and apparatus for providing an easy to remove seal in a disposable toner cartridge during remanufacture which prevents the leakage of toner during shipment of the remanufactured toner cartridge.
2. Description of the Prior Art
Toner cartridges of the type commonly used with laser printers and the like typically may be used for 2000-20,000 prints before the toner is exhausted. Most laser printer manufacturers direct the user to discard the old toner cartridge, which also includes a magnetic roller, gears and other parts, and to purchase a new cartridge which is filled with toner. For example, the IBM Lexmark 4019, 4028, 4029 and 4039 imaging cartridges are designed to be disposable and are thrown away when the toner is depleted. Since many useful parts are discarded with the empty toner cartridge, disposal of the toner cartridge is quite wasteful and expensive. However, wear and tear on the toner cartridge during use renders simple refilling of the toner cartridge virtually impossible; reconditioning or remanufacturing of the toner cartridge prior to refilling is often necessary. Moreover, it is undesirable for the user to have to deal directly with the toner since it is quite messy.
Numerous companies have taken steps to minimize such waste by remanufacturing or reconditioning toner cartridges for reuse. Remanufacturing of the toner cartridge is a cost effective and environmentally conscientious alternative to disposing of the toner cartridge since it can be done quite readily by replacing all the worn and broken components of the toner cartridge. Unfortunately, remanufacturers continue to have difficulty with shipping the remanufactured and refilled toner cartridges to their customers since it has proven quite difficult to provide a seal which prevents the leakage of the toner out of the remanufactured toner cartridge. This problem has stymied further customer acceptance of remanufactured toner cartridges.
The original equipment manufacturer does not have as much of a problem with toner leakage because, when the toner cartridge is new and filled with toner, all the tolerances of the elements of the toner cartridge are tight by comparison to a used toner cartridge. In other words, fewer gaps are present through which the toner may leak. This is especially true in the critical sealing area around the feed roller due to the material used (mylar and plastic) and the number of prints the typical toner cartridge delivers before running out of toner. Since new toner cartridges may be shipped without substantial toner leakage, many customers still prefer to wastefully dispose of the used toner cartridges and to replace them with new toner cartridges. Accordingly, it is desired to provide a sealing mechanism for remanufactured toner cartridges which substantially prevents the leakage of toner so as to improve customer acceptance of remanufactured toner cartridges.
Numerous attempts have been made in the art to provide seals which prevent the leakage of the toner during shipment of the toner cartridge. For example, an adhesive backed film capable of retaining the toner inside the toner cartridge during shipment has been used to prevent leakage of the toner. Such sealing systems for toner cartridges are described by way of example in the following U.S. Pat. Nos. 4,062,385 to Katusha et al; 4,778,086 to Shibata et al; 4,924,920 to Bhagwat; 4,930,684 to Patterson; 4,961,450 to Furuta; 5,018,560 to Tsukamoto; 5,080,745 to Paull; 5,110,646 to Prestel et al; 5,150,807 to Seyfried et al; 5,153,643 to Nagakura; 5,184,182 to Michlin; and 5,194,900 to Hagihara et al. However, the seals used in those systems are either difficult to remove by the customer, prohibit adequate testing prior to shipment of the remanufactured and refilled toner cartridge, and/or cause a substantial amount of toner to leak out when the seal is removed, thereby causing toner to cover the customer and his or her clothing.
Other seals have been proposed which seal the remanufactured toner cartridge for mailing while further preventing leakage of the toner during removal of the seal. For example, a "wind-up" style seal has been used in which a piece of adhesive backed film is used to obtain a seal at one end of the toner cartridge at the toner feed roller. The other end of the adhesive backed film is attached to a large internal auger which the user turns to slowly wind up the adhesive backed film, thereby removing the adhesive backed film from the toner feed roller and permitting the toner to flow down to the developer roller. Such a system has the advantage that the seal may be removed without leaking toner onto the customer or the customer's clothing. However, due to the slow large internal auger movement, the customer must run approximately 25 prints on the toner cartridge before clean copies may be obtained. A simpler, more easy to use, and less wasteful system is desired.
Still other toner cartridges have been designed which use a removable seal and a wiping element to minimize toner leakage when the seal is removed. For example, as described by Yoshino et al. in U.S. Pat. No. 4,895,104 and Kita in U.S. Pat. No. 5,206,619, the sealing tape may be pulled through a cleaning pad or a sealing member such as a sponge so that the toner is wiped off the adhesive as the seal is removed directly by the user. Such seals are quite easy to remove without the leakage of toner onto the customer or the customer's clothing; however, such seals have not been provided in the context of remanufactured toner cartridges and thus do not account for the variations in the manufacturing tolerances of the feed roller and the like during use. On the contrary, the seals disclosed by Yoshino et al. and Kita are used in conjunction with toner cartridges which the customer uses for refilling reusable toner cartridges and cannot be used over and over again. Thus, an easy to remove seal for toner cartridges which prevents the leakage of toner is still desired in order to improve customer acceptance of remanufactured toner cartridges.
Accordingly, there is a long-felt need in the art for an easy to remove seal which accounts for variations in the manufacturing tolerances of the feed roller and the like during use. The present invention has been designed to meet this need.